In the United States, heart disease is the most common cause of death in both men and women and heart failure (HF) is the common endpoint and a major health problem in the aging population. Exercise is beneficial to heart function; however, there has long been much debate about the use of exercise training in older HF patients. The usual recommendation for patients with chronic HF has been restriction of physical activity. Recent studies in HF patients have shown that exercise does improve heart function; however, exercise training is not widely used because the data on its effect on survival are not very compelling. Lacking in current literature is the effect of exercise training on survival in HF patients. In a recent study 15 mo. old male SHHF (Spontaneously Hypertensive Heart Failure) rats, a natural genetic animal model of HF, completed 6 months of 3 day a week moderate treadmill running. It was found that 4/5 of the sedentary controls developed overt HF while none of the runners did. The SHHF rat model has a number of biochemical, physiologic, and gene alterations observed in humans with HF and responds in a similar manner as human HF patients to drugs currently used in HF. Since all SHHF rats are genetically programmed to develop HF, true survival studies can be performed. In this proposal we will determine how exercise will increase the survival of older male SHHF rats using 8 and 15 mo old rats since exercise might modify the onset of HF depending on the condition of the heart at the start training. They will be exercise trained until they develop overt HF. Serial echocardiograms will be done to determine how the heart function is altered by exercise. Our long term goal is to establish that exercise training increases longevity by improving heart function and altering gene programs and biochemical pathways in the heart. These studies could provide a highly compelling reason for adding the use of moderate exercise to the treatment regime of older HF patients and could result in the reduction in drug therapy.